Topic: Hard Drive vs Me

[RossRoy]

Will you allow me a little rant here?

Last week I thought I should make my NAS larger. So, I went out and bought a 1TB hard drive to replace the smallest one currently in service (a 320GB).

I was aware of that new so called "Advanced Drive Format" (ADF) but didn't think much of it.

When I got the HDD, what do you know! It IS an ADF drive. So I went online to find out what it implies - Western Digital says pretty much everywhere that only Windows XP and lower are affected, ALL other OS are fine.

So OK, I go ahead and change the drive. Of course, my RAID is now degraded. So I take it offline and proceed to partition my drive.

First oddity: diskinfo reports sector size as 512Bytes. (Should 4096Bytes) but I thought so what!

So I made sure my partitions are aligned with the 4K sector sizes and proceeded to partition and format the drive.

I then issued the replace command to add the drive to my RAID.

My gosh! Can you believe a SATA drive writing at the blindening speed ok - 0.5MB/sec

Turns out the hard drive itself is doing some whoolas internally for translate the 512B sectors in 4K sectors - which makes sense but it shot speeds right down to hell!

But, why in the first place, doesn't it report a 4K sector size? And there's no jumper setting to make it report 4K sector sizes.. at least none I've found..

Furthermore, I understand the advanced format is not to improve speed, but to increase possible total capacity. Then why in the hell release 1TB drives with advanced format when it as all fine before?

Grrrrr.. I have no idea what I'm going to do.. Guess I'll return it to the store and try to find a non-advanced format drive... or one that reports its internal workings correctly!

[Touti]

Seb I got a few of those WD Advanced formatted drive, I've become some kind of an expert on them.  A few questions.

1: Do you have a jumper on pin 7 and 8, I know you said there's none that you found.  If there was they would be on 7 and 8 but it doesn't come that way so I'm guessing you don't.
2: What OS did you use to partition the drive.
3: How did you "make sure it was aligned with the 4K sector size"


A bit of information on those drive.  Why are they releasing them ?  Advanced formatted drive are becoming the new standard but for some stupid reason WD has decided to try and "silently" push the format so they release these drives without talking much about it.  The problem is that their so called "silent" thing isn't so silent anymore since many people have problems with them.  Trust me, these have been the talk of the day for quite some time on WHS forums.

I can tell you more on how to make it work once I get more info from you but in the meantime here's a few things to know.


1: WD isn't very clear when they say it only affects XP.  In fact the problem affects any windows OS that isn't based on the Windows 6 core, that is anything before Vista so this is also a problem on 2000 and 2003.  It it is not a problem on Vista, Windows 7, and all flavors of Windows 2008.

2: The problem really comes from those windows OS that are based on XP because for some very stupi reason MS has decided to force the first partition to start on sector 63 instead of 64.  Advanced formatted drives, using 4k sectors have their first partition starting on sector 64 like most OS'.  This means that sometimes a 512 bytes sector can actually spread over two 4k sectors.  Because the drive will naturally write one 4k sector at a time, to deal with a misaligned partition it needs to read and rewrite each sector for every write commands it receives.  That is why they run so slow when they're misaligned.

3: The jumper on pins 7 and 8 is a bit of a crude hack from WD but it works well as long as there's only 1 partition on the drive.  In pretty simple terms, it instruct the hard disk to write every byte at the address specified by the OS + 1 byte.

4: There is absolutely no problem in running a 4K sectors drive in Windows XP as long as the partitions are aligned after they're created.  The best way to do that is to download an ISO file from WD that creates a boot CD which does it.  There's also a program to do it but it's much slower.  I must tell you that the more data you have on the drive the longer it's gonna take so do yourself a favor and re-aligned your partitions right after you create them.  I've done it on 3 of my drives and on a newly partitioned and empty 1TB or 2TB drive it only takes about 30 seconds.  Others have done this on 1TB drives loaded with data and it took hours.  The align utility will really move every byte of data.

5: I don't know how your NAS Works but if it allows you to add an already partitioned drive to your raid then you can create the partition in your computer using Windows 7 and then add it your NAS.  Windows 7 will recognize this drive as an advanced formatted one and create the partition at the right place.

[Najemikon]

If the NAS is stand-alone, it might be embedded Linux. I'm sure I read somewhere that ADF wouldn't be happy with those either.

Long term, ADF does make sense, but it's going to be a pain in the arse in some cases.

[Touti]

Here's a link to the best article I found on the subject when I first got one of these drives.
http://anandtech.com/show/2888


And here's a link to the download page for the ISO version of the align utility.
http://support.wdc.com/product/downloadsw.asp?sid=122


And Seb, there is a gain in speed with these drives even when under 2TB.  Most files in today's world are bigger than 4K, dealing with 4K at a time instead of 512 bytes reduces the amount of I/O operations by a factor of 8.  That's not negligeable.

But I understand your frustration since I went through the same and honestly, I believe WD fucked up big time on this one by trying to make the migration transparent.

[RossRoy]

I'm running my NAS on FreeBSD (Freenas). I just read on there that there's a fix for ADF that's been commited, so I just have to wait for the next build to be released. SO in that aspect, it isn't too bad.

As for how I tried to align it - I used GPT to partition it. I can tell it where to place the partitions. So I made the first partition to start on the 64th sector (which should be on a 4K boundary) and I made sure the size of the partition was dividable by 8 pseudo-512B sectors.

Anyways, I've given up and am waiting for the fix to be released. I don't really need the extra space yet - i just wanted to improve the performance of my Win7 PC so I was going to take the 320GB, replace it in the NAS by a 1TB, and then build a striped raid with 2 320GB.

This'll just have to wait a bit hehe

[Kathy]

I thought this was another of my friend Jimmy's threads!